A sporting event typically is recorded by a plurality of cameras placed at locations around the venue, with each camera location providing a different view of the sporting event. For example, in a baseball game, one camera, placed beyond the outfield fence, records the batter from the perspective of the pitcher; another one, placed in or near the dugout, records the batter from the side. A director, who may be located in a production truck outside the stadium or remotely at a production studio, is responsible for creating a broadcast program from all the camera feeds. Using a standard production switcher, the director creates a broadcast program consisting of a sequence of scene cuts switching from one camera feed to another. In the case of baseball, for example, the director may initially select to broadcast the feed from the dugout camera at the beginning of an at-bat to show the batter in perspective; once the pitcher is about to deliver a pitch, the director then cuts the program from the feed of the dugout camera to that of the outfield camera, which can zoom in on the pitcher throwing the ball to the catcher and the batter swinging (or not) at the pitch. In reality, a sporting event involves many more than two cameras, since a broadcast of such an event requires it to be recorded from many different views, with each view being recorded by its own respective camera. Typically, the feeds of all these cameras are supplied to a production switch, where the director dictates the sequence of camera feed cuts to constitute the program for broadcast.
A more recent development in the field of producing video programs for broadcast involves the insertion of indicia or logos (graphics) into the video signals generated by the cameras. Electronic devices for inserting graphics into live video signals, such as described in U.S. Pat. No. 5,264,933 by Rosser, et. al., U.S. Pat. No. 5,488,675 by Hanna, U.S. Pat. No. 5,491,517 by Kreitman et. al., U.S. Pat. No. 5,953,076 to Astle et al., and U.S. Pat. No. 5,808,695 to Rosser et al., all of which are hereby incorporated by reference, have been developed and used for the purpose of inserting advertising and other indicia into broadcast events, primarily sports events. These devices are capable of seamlessly and realistically incorporating logos or other indicia into the original video in real-time, even as the original scene is zoomed, panned or otherwise altered in size and perspective. An indicia insertion system unit typically performs the main functions of recognition using a recognition unit, tracking using a tracking unit, occlusion mask production using an occlusion mask production unit, and rendering using a render unit where the indicia are inserted into the video frame based on the occlusion mask.
The insertion of such logos or other indicia is intended to enhance the viewing experience of end viewers. For instance, in football, a first down line (“FDL”) is inserted into the real-time broadcast of a game to signify the point on the field that the team currently on offense must drive towards in order to be awarded four more downs. Other virtual elements are not related to the game itself, but instead comprise advertising indicia inserted at various points on the field of play or on various stadium structures like a stadium wall. Indicia may contain any type of information, including 1) game related statistics, 2) sports, team, or athlete specific data, 3) viewer's related data, or 4) any generic information such as weather, news titles, stocks, etc.
Many ways exist to carry out indicia insertion capabilities in a multi-camera system intended for recording and broadcasting a sporting event. One such way is known as the “brute force” implementation, in which each video camera is provided with its own indicia insertion system. With this approach, all video camera feeds appearing at the input of the production switch will already have had inserted therein any desired indicia. For instance, the camera feed pertaining to the sideline of a football field will arrive at the production switch with a logo or indicia (e.g., an FDL) having already been inserted by the insertion system associated with the sideline camera.
Associating a separate logo insertion capability with each camera of a multi-camera system can introduce many limitations. For instance, the multiple insertion systems occupy a great deal of space in the production truck, which makes the truck much heavier and thus raises its fuel costs and consequently the production costs for the event.
Another problem stems from the fact that in such a system, if a feed has had inserted therein a logo by its associated insertion system, the director at the production switch, when previewing such a feed, must either accept the feed as is or must reject it in favor of a “clean” feed (i.e., a feed without any insertion of indicia) or a feed from a different camera. Typically, when previewing the feeds before selecting one for cutting into the broadcast program, the director cannot readily compare the feed with the inserted logo against the clean feed, either because a clean version is not available or if available it is not in synchronization with the enhanced version. This is especially a problem when the indicia appear to the director to lack that seamlessness and realism that are necessary to create the illusion that the indicia actually is part of the scene being recorded.
Still another problem in multi-camera systems used to film sporting events is the inability to include indicia insertions in highlight clips, also referred to as playback clips. This inability is due to several complications: 1) the playback clip is typically a zoomed-in shot that does not contain enough features to allow recognition and tracking by the insertion system, and 2) the highlight clip is often slowed down to allow the viewers to follow the play, which may cause the tracking function of the insertion system to fail.